Polymerization of allyl cyclohexane with a friedel-crafts catalyst



United States Patent "ee 352979672 Patented Jan. 10, 1967 methyl 4 alkyl cyclohexane; 1 phenyl 4 vinyl cyclo- 3,297,672 hexane; 1-(2,4-dimethylcyclohexyl)-vut-4-ene-1 and 5- POLYMEFJZATION 0F ALLYL CYCLOHEXANE vinyl-2,4-bicyclooctane and the like are operable to yield WITH A FRIEDEL'CRAFTS CATALYST the novel 01 mer structures of this invention due to the Arthur Donald Ketle Olney and Raymond J lEhi-r p Silver Sprin Md assignors to W R Grace & C0 5 rate of carbonium ion rearrangement being faster than New York YQ corporation of 'Cm'mecficut the propagation rate under the conditions of this inven- N p ifi Fi 9 19 3 s N 301,207 tion. Other substituents, aside from alkyl groups, may

15 Claims. (Cl. 26093.1) be placed on the cyclohexyl ring and result in novel-polymers without affecting the reaction as long as said substit- This invention relates to novel polymer composltlons 10 uents do not complex with or otherwise destroy the and a process for producing same. More particularly this Friedel-Crafts catalyst. Hence the criticality of substituinvention is concerned with polymerizing olefins of the ent selection is whether or not the substituent complexes or formula: destroys the Friedel-Crafts catalyst. Such a selection is f obvious to one skilled in the art. s \OH2/ 0H=CH2 At the low reaction temperatures of this cationic polymerization the rate of carbonium ion rearrangement is Whfle n is an integer from 0 to 3. faster than the rate of propagation. For example in It is known in the art to polymerize olefins of the for- P t i vmyl q the secondary carbonium ion, WhlCh is the propagating end, rearranges to a tertiary mula' carbonium ion by a 3,2-hydride shift prior to propagation fCHrCHt of the polymer chain. This results in a polymer having ir, C II (CH2) 1, predominantly the following recurring structural unit:

CID-CH2 where n is an integer from 0 to 3, by subjecting said olefins to the action of a Ziegler type catalyst at temperatures in the range 20 to 100 C. The polymeric product obtained has the recurring structural unit L /l '/CHCH2) l In the ordinary case of polymerizing vinyl cyclohexane with a Ziegler catalyst at temperatures from 20 to 100 C. the resulting polymer has exclusively the following re- S curring structural unit:

01101-12 where rt is as defined above. See K. R. Dunham, J. Van I Den Berghe, J. W. H. Faber and L. E. Contois, J. Polymer 40 Sci. (A) 1, 751 (1963). s

Surprisingly it has now been discovered that where an olefin of the formula,

OHPGH2 4 Thus it is seen that a novel polymer composition is formed by the practice of this invention.

One method of determining the recurring structural OHr-OI-Iz unit in the resultant polymer product is by the use of infrared spectroscopy. wherein n is an integer from 0 to 3 inclusive, 1s Sub ected The normal Zieg1er Natta polymers of these cyclohexyl to the action of a Friedel-Crafts catalyst in the presence monomers h l one methylene group per monomer of a cocatalyst selected from the group conslstmg of a unit in the backbone The F i d lic ift pqlymers have (1030f p g n( frf ypfiggtg so t 12:38 two 0; gore methylene grofilps. This glfveil rise to signifian a car nlum 1 S 11 cant i erences etween t e spectra 0 t e two sets of safily in an inert Solvent h telilperamredin 53 55 olymers in the methylene rocking region of the inframinu 30 t minus e P Y P 0 tame red i.e. (700 cm. 800 cm. For example, the band at contains predominantly the recurring structural unit, 52 1 in cationic poly 3 methylbutene l h been signed to the skeletal rocking mode of the {-CH CH group. See J. P. Kennedy, J. Polymer Sci. (in press 1963). This band is completely absent in the Ziegler- Natta polymer. A similar assignment has been made by S Van Schooten and Mostert for this band in ethylene-propylene copolymers. See Polymer, 4, 135 (1963). The

\/ same Workers assign a band at 730 cm." to {-CH sequences. Methylene rocking vibrations in side-chains where n is an integer from 0 to 3, said integer being the and end-groups have somewhat higher frequencies; for same integer as in the olefin monomer'reactant. example, the tCI-I CH CH in the terminal propyl The cyclohexyl group attached to the terminal carbon group of polypropylene absorbs at 740 cmf See M. C. atom in the monomers employed as reactants in the in- Harvey and A. D. Ketley, J. App. Polymer Sci., 34, 533

stant invention may, if desired, be substituted with alkyl (1959), while bands at 700-770 cm. have been asgroups as will be shown by an example hereinafter. Thus signed to the -CH group in the side-chains of several such monomers as 1-isopropyl-4-vinyl cyclohexane; 1- polymers.

The infrared absorptions in the methylene rocking region of polymers prepared with Friedel-Crafts catalysts are shown in Table I together with assignments of these bands.

TABLE I.-METHYLENE ROCKING ABSORPTIONS OF POLYCYCLOIIEXYL ALKENES PREPARED WITH FRIE- DEL-CRAFTS CATALYSTS The positions of these methylene rocking bands support the structures proposed for these polymers.

The following examples are set down to aid in understanding but expressly not to limit the invention. Unless otherwise specified all parts and percentages herein are by weight.

Example 1 1.0 gm. AlBr catalyst was dissolved in 250 ml. of ethyl chloride and cooled to minus 50 C. The cooled catalyst solution was charged under nitrogen to a 1 liter nitrogenpurged resin kettle equipped with stirrer, thermometer, Dry Ice condenser and gas inlet and containing 18.9 gms. of vinyl cyclohexane. The kettle was maintained at a temperature of minus 80 C. by a low temperature bath. After a reaction period of 20 minutes under nitrogen with agitation, polymer was noticeable. The reaction was continued for 3 hours after which 20 cc. methanol was added to stop the reaction. The polymer product was washed, ground, filtered and dried overnight in a vacuum oven. The dried polymer weighed 6.8 gms. (36% monomer conversion), had a softening point of 93 C., and a number average molecular weight of 10,500. On characterization by infrared spectroscopy a sample showed a sharp band at 742 cm.- Such absorption is characteristic of the tcHm group in A control run was made using polymer obtained from polymerizing vinyl cyclohexane in the presence of a Ziegler catalyst in heptane solvent at a temperature of 55 C. and a pressure of 1 atm. The Ziegler catalyzed polymer showed no infrared absorption in the region 700-800 cm? in agreement with the accepted structure Example 2 28 ml. ethyl chloride containing 0.25 g. AlBr were condensed under a N atmosphere in a 50 ml. nitrogen purged flask equipped with stirrer, thermometer, Dry Ice condenser and gas inlet. The kettle was maintained at a temperature of --113 C. by immersing it in a cooling bath. Under nitrogen, 5 ml. of vinyl cyclohexane previously dried over CaH was added to theflask in 25 ml. ethyl chloride at 113 C. The reaction, with agitation,

was continued under N for 3 hours. Excess methanol was added to the kettle to stop the reaction. The polymer was then ground in fresh methanol, filtered and dried overnight in a vacuum oven at 25 C. The dried polymer product (0.3 gm.) was a glassy material having a number average molecular weight of 12,700 determined in benzene solutions using a Mechrolab vapor pressure osmometer. On characterization by infrared spectroscopy the polymer had the recurring structural unit:

and had a softening point of 120 C.

Example 3 Example 2 was repeated except that 5 ml. of allyl cyclohexane was substituted for vinyl cyclohexane. The resulting polymer product on characterization by IR was predominantly a polymer having the following recurring structural unit:

and had a number average molecular weight of 13,100 and a softening point of C.

Example 4 Example 2 was repeated except that 4 ml. of 4-cyclohexyl butene-l was substituted for vinyl cyclohexane. The resulting polymer product on characterization by IR was predominantly a polymer having the following recurring structural unit:

and had a number average molecular weight of 7200.

Example 5 Example 2 was repeated except that 5 ml. of cyclohexyl pentene-l was substituted for vinyl cyclohexane.

The resulting polymer product on characterization by IR was predominantly a polymer having the following recurring structural unit:

The polymer was a rubbery material, having a glass transition temperature of 0 C. and a number average molecular weight of 4450.

Example 6 Example 2 was repeated except that 5 ml. of l-isopropyl-4-vinyl cyclohexane was substituted for vinyl cyclohexane. The resulting polymer product on characterization by IR was predominantly a glassy polymer having the following recurring structural unit:

C CH3 C H:

The polymer product had a number average molecular weight of 10,600 and a softening point of 110 C.

The polymerization reaction is performed at a temperature in the range minus 30 to minus 150 C. At higher temperatures the rate of propagation is faster than the rate of rearrangement via the hydride shift thus resulting in predominantly unrearranged, low molecular weight polymer products.

Preferably solutions containing from 1-10% by weight of monomer are used. Any solvent in which the monomer dissolves and preferably in which the polymer formed precipitates and which remains liquid under the reaction conditions is operable. Obviously the solvent must also be one which does not react with or kill the catalyst. A preferred class of solvents includes but is not limited to chlorinated hydrocarbons. Example of said preferred class of solvents include methyl chloride, butyl chloride, ethyl chloride and the like. Saturated hydrocarbons such as butane, propane and pentane are also operable as solvents in the instant invention. Other well known solvents are obvious to one skilled in the art.

As used herein the term FriedeLCrafts catalyst means any Lewis Acid capable of initiating cationic, that is, carbonium ion type polymerization. Examples of Friedel- Crafts catalyst include, but are not limited to, AlCl AIBI3, B123, SnCl The amount of Friedel-Crafts catalyst used in this invention can be varied within wide limits. A monomer: Friedel-Crafts catalyst weight ratio in the range 100:1- 1:1 is operable in performing this invention.

The polymerization reaction is performed in the presence of a co-catalyst selected from the group consisting of a proton donor and a carbonium ion source. Examples of operable proton donors include, but are not limited to, water and any Bronsted acid. Alkyl halides are one type of carbonium ion source operable in this invention. Where an alkyl halide is used as the solvent as in Example v2 herein, no additional co-catalyst is necessary. When an inert saturated hydrocarbon, erg. butane is used as the solvent in the instant invention, normal drying procedures leave sufiicient moisture in the solvent to act as a proton donor co-catalyst. Nor is the donor proton or carbonium ion source co-catalyst concentration critical. The invention is operable with amounts ranging from a trace, e.g. 0.01% by weight of the Friedel-Crafts catalyst concentration up to amounts in great excess over the amount of Friedel-Crafts catalyst employed as evidenced by the use of ethyl chloride as co-catalyst and solvent in Example 1.

The polymer products of the instant invention have many and varied uses. The polymer products due to the rearrangement by means of the hydride shift are glassy materials. Thus the polymer products can be used in any application where a highly transparent, hard polymer is required. Such uses include clear containers, rear lights for autos, decorative mouldings, etc.

The softening point of the polymer products of the instant invention was measured as the temperature at which the polymer begins to flow on a Fisher Johns melting block.

The number average molecular weight of the polymer products of this invention were measured on a Mechrolab vapor pressure osmometer, Model 301-A manufactured by Mechrolab Inc., Mountain View, California, in accord with the instructions therefor.

The glass transition temperature of the glassy polymer products of this invention is defined as the point where the thermal expansion coefficient undergoes a discontinuity as measured by dilatometry in accord with the method of Bek-kedahl, N.; I. Research, Natl. Bur. Standards, 43, (1949).

The IR spectra of the polymer products of the instant invention were obtained with a Perkin-Elmer 21 IR spectrometer using solid films of the polymer, 0.5-1 mil in thickness.

What is claimed is:

1. A solid glassy type polymer having predominantly the following recurring structural unit is a cyclohexyl group and n is an integer from 0 to 3 inelusive.

2. A solid glassy type polymer having predominantly the following recurring structural unit c 3. A solid glassy type polymer having predominantly the following recurring structural unit OHzCH2CH2- the following recurring structural unit CHrC HzC H2CHZ where 5. A polymerization process which comprises subjecting an olefin of the formula:

is a cyclohexyl group and n is an integer from 0 to 3 inclusive, to the action of a Friedel-Crafts catalyst and a co-catalyst selected from the group consisting of a proton donor source and a carbonium ion source at a temperature in the range minus 30 to minus C.

6. The process according to claim 5 wherein the polymerization reaction is performed in a solvent.

7. A polymerization process which comprises subjecting vinyl cyclohexane to the action of a Friedel-Crafts catalyst and a co-catalyst selected from the group consisting of a proton donor source and a carbonium ion source at a temperature in the range minus 30 to minus 150 C.

where 8. The process according to claim 7 wherein the polymerization reaction is performed in a solvent.

9. A polymerization process which comprises subjecting allyl cyclohexane to the action of a Friedel-Crafts catalyst and a co-catalyst selected from the group consisting of a proton donor source and a carbonium ion source at a temperature in the range minus 30 to minus 150 C.

10. The process according to claim 9 wherein the polymerization reaction is performed in a solvent.

11. A polymerization process which comprises su bjecting 4-cyclohexylbutene-l to the action of a Friedel-Crafts catalyst and a co-catalyst selected from the group con.- sisting of a proton donor source and a carbonium ion sourge'at a temperature in the range minus 30 to minus 15 0" C.

/ 12. A polymerization process which comprises subjecting S-cyclohexylpentcne-l to the action of a Friedel-Crafts catalyst and a co-catalyst selected from the group consisting of a proton donor source and a carbonium ion source at a temperature in the range minus 30 to minus 13. The process according to claim 11 wherein the polymerization reaction is performed in a solvent.

14. A solid glassy type polymer having predominantly the following recurring structural unit References Cited by the Examiner UNITED STATES PATENTS 2,931,791 4/1960 Ernst et al. 260-93.l

JOSEPH L. SCHOFER, Primary Examiner.

L. EDELMAN, Assistant Examiner. 

1. A SOLID GLASSY TYPE POLYMER HAVING PREDOMINANTLY THE FOLLOWING RECURRING STRUCTURAL UNIT
 5. A POLYMERIZATION PROCESS WHICH COMPRISES SUBJECTING AN OLEFIN OF THE FORMULA: 